1. Field of the Invention
This invention relates generally to a system and method for adaptive lane centering in an autonomously driven vehicle and, more particularly, to a system and method for providing an adaptive driving-based lane offset control for the lane centering system.
2. Discussion of the Related Art
The operation of modern vehicles is becoming more autonomous, i.e., the vehicles are able to provide driving control with less driver intervention. Cruise control systems have been on vehicles for a number of years where the vehicle operator can set a particular speed of the vehicle, and the vehicle will maintain that speed without the driver operating the throttle. Adaptive cruise control systems have been recently developed in the art where not only does the system maintain the set speed, but also will automatically slow the vehicle down in the event that a slower moving preceding vehicle is detected using various sensors, such as radar and cameras. Other variations of modern vehicle control systems include autonomous parking where the vehicle will automatically provide the steering control for parking the vehicle, intervening if the driver makes harsh steering changes that may affect vehicle stability and lane centering capabilities where the vehicle system attempts to maintain the vehicle near the center of the lane. Further, fully autonomous vehicles have been demonstrated to drive in simulated urban traffic up to 30 mph, observing all of the rules of the road.
As vehicle systems improve, they will become more autonomous with the goal being a completely autonomously driven vehicle. For example, future vehicles will likely employ autonomous systems for lane changing, passing, turns away from traffic, turns into traffic, etc. As these systems become more prevalent in vehicle technology, it will also be necessary to determine what the driver's role will be in combination with these systems for controlling vehicle speed, steering and overriding the autonomous system.
Examples of such systems include U.S. patent application Ser. No. 12/399,317, titled “Model Based Predictive Control for Automated Lane Centering/Changing Control System,” assigned to the assignee of this application and herein incorporated by reference, which discloses a system and method for providing steering angle control for lane centering and lane changing purposes in an autonomous or semi-autonomous vehicle. U.S. patent application Ser. No. 12/336,819, titled “Detection of Driver Intervention During a Torque Overlay Operation in an Electric Power Steering System,” assigned to the assignee of this application and herein incorporated by reference, which discloses a system and method for controlling vehicle steering by detecting a driver intervention in a torque overly operation. However, to accommodate a wide array of personal driving preferences, the lane centering system needs to provide an adjustable lane centering offset control capability.